Where maternity is concerned, studies are quick to generalise. But when paternity comes in, research hardly ever gets further than the testicles.

The 21st century has been relatively kind to women in the workplace: homemaker is no longer seen as the pinnacle of female ambition; law, medicine and engineering have all seen impressive numbers of female students (with ‘warnings’ from the Royal College of Physicians suggesting that by 2017, most doctors will be women); all-women political shortlists have seen encouraging results in the Labour party. The time is gone when men retired from the dinner table to ‘talk politics’ while their womenfolk expressed a love of kittens to one another in a constant feedback loop. And it all happened fairly quickly: there is certainly a generation alive today who sat at that dinner table.

What has survived all of this progression is the idea that no matter what sort of a career a woman pursues – whether publishing, lecturing, nursing, computer game designing, or engaging in armed combat – her maternal instinct will win out. Discussions about whether women can ‘have it all’ imply that ‘all’ for women necessarily includes children. And yet procreation is going out of fashion: the average British family has 1.7 children, statistically miles away from the oft-quoted 2.4 of years gone by.

Perhaps it’s because we’re educating women too much that they’re refusing to breed. That certainly seems to be the view of (male) researcher Satoshi Kanazawa, an analyst at the London School of Economics who ‘found’ that the maternal urge of women decreases with every 15 IQ points. Setting aside the fact that measuring intelligence is a highly sketchy art at best, and measuring ‘maternal instinct’ presumably even sketchier, the media has been quick to label Kanazawa’s findings ‘innovations’. “If any value is truly unnatural, if there is one thing that humans (and all other species in nature) are decisively not designed for, it is voluntary childlessness,” Kanazawa then writes in his book The Intelligence Paradox, brazenly throwing around the terms “unnatural” and “designed for” like so many toys out of a rare baby’s pram.

When it comes to maternity, intelligence is first in the firing line. But when it comes to paternity, we clearly have other concerns. Emory University in the US has found a definitive link between the parenting involvement of a man and the size of his testicles, according to BBC News. In a nutshell (no pun intended), the results were: small testicles, better daddy. Researcher Dr James Rilling commented: "It tells us some men are more naturally inclined to care-giving than others, but I don't think that excuses other men.” Quite.

When maternity is investigated, it is all too often extrapolated into evolutionary theory, the downfall of the species, and the potential collapse of western society. Where paternity is concerned, testicles are about as far as you get. The most telling part of Emory’s study is the disclaimer that “cultural and societal expectations on the role of the father are... not accounted for in the study.” Meanwhile, Kanazawa’s “paradox” is found in the idea that smarter women might not be doing as much as what they were “designed for”. Perhaps it’s another one of those pesky social factors. Like not wanting to.

Either way, I think I’d rather have my (huge, metaphorical) testicles measured than be told that my intelligence quotient is a problem for my ovaries.